A legend (Latin, legenda, "things to be read") is a narrative of human actions that are perceived both by teller and listeners to take place within human history and demonstrating human values, and which possesses certain qualities that give the tale verisimilitude. Legend, for its active and passive participants, includes no happenings that are outside the realm of "possibility", but may include miracles. Legends may be transformed over time, in order to keep them fresh and vital, and realistic. Many legends operate within the realm of uncertainty, never being entirely believed by the participants, but also never being resolutely doubted.